Could Australia's next conservative Deputy Prime Minister be the son of an expatriate New Zealand farmer, a former nightclub bouncer who has outraged his senior political partners by voting against them?

Barnaby Joyce, a senator from rural Queensland and leader of the Nationals in the Upper House, might be a heartbeat away from the nation's top job if he succeeds in his plan to oust independent MP Tony Windsor from his New South Wales seat.

After two terms in the Senate, Joyce has confirmed he wants to move to the House of Representatives, from where he can launch a bid to replace Warren Truss as leader of the Coalition's junior partner.

He has been encouraged by a series of polls placing Prime Minister Julia Gillard's fragile minority Government in deep trouble and by the backlash against independent MPs in the recent NSW state election.

That election reduced the former Labor Administration to a diminished rump in the state Parliament and ousted independents in electorates embraced by the federal seats held by Windsor and Rob Oakeshott, both former Nationals whose support holds Gillard's Government together.

The federal Opposition is a coalition between the Liberals and the smaller, rural-based Nationals, and if leader Tony Abbott was to displace the struggling Gillard as Prime Minister at the next election, the Nationals would hold the deputy's position.

The prospect of Joyce holding that job was immediately exploited by Gillard.

"Is Tony Abbott going to the next election saying to Australians that Barnaby Joyce would be Deputy Prime Minister, that Barnaby Joyce is the man who would act as Prime Minister if Tony Abbott was away overseas?" she said. "If that's Tony Abbott's plan for the future of the country he should be crystal clear about it."

Joyce has been an eccentric, strong-willed and independently-minded force in Canberra since he arrived in the Senate in 2005, repeatedly crossing the floor to vote against former Prime Minister John Howard's conservative government.

His father, James, crossed the Tasman to study veterinary science and became a farmer near Tamworth, in the northern NSW highland region of New England, where Joyce was born and raised.

Joyce gained a commerce degree, worked variously as a bouncer - once famously requiring 28 stitches after a brawl - and as a banker before setting up as a rural accountant in St George, a small town in cotton country west of Toowoomba.

He has always championed agriculture, rural Australia and conservative social values, argues against foreign takeovers of key resources and has often infuriated Liberal colleagues.

"To tell you the truth, I have never really liked Liberals much," he told one interviewer. "They all think they have something special happening in their lunchbox."

His independence has been welcomed by many National voters, who have watched their party decline for years, slipping from 19 seats in 1996 to just six at the last election.

Joyce has often been considered a potential Nationals leader and, while rejecting a challenge to Truss, victory over Windsor would put him in a pole position for the job.

Joyce could have a reasonable chance in New England, a conservative rural seat lost to Labor only once - in 1906 - since it was proclaimed at federation.

Windsor, a disenchanted National, won it in 2001 and has held it since, maintaining a strong margin at last year's election. Joyce told ABC radio voters had been very disappointed at Windsor's decision to back Gillard and, more recently, her proposed carbon tax.

He said he could not stand for the Lower House in his own area because it was already held by the Nationals, and had chosen New England because he grew up there.

But he said the decision rested with local party members: "You do not invite yourself to a wedding, you wait for the invite to turn up."

Windsor said Joyce had a "messianic" view of himself, and welcomed a contest.

"If he wants to leave the people of Queensland that he says have been so good to him, that's his business." he said. "If he wants to come to New England, that's his business ... I welcome the competition."

Truss said the Nationals could win the seat - although it would be a challenge - and that Joyce "would certainly provide an important focus for us in that electorate".